MongoDB is a NoSQL database that offers a high performance, high availability, and automatic scaling enterprise database. MongoDB is a NoSQL database, so you can't use SQL (Structured Query Language) to insert and retrieve data, and it does not store data in tables like MySQL or Postgres. Data is stored in a "document" structure in JSON format (in MongoDB called BSON). MongoDB was first introduced in 2009 and is currently developed by the company MongoDB Inc. There are Ubuntu packages for MongoDB available for LTS releases only.

Prerequisites

Ubuntu Server 14.04 - 64 bit

Root privileges

What we will do in this tutorial:

Install MongoDB

Configure MongoDB

Conclusion

Install MongoDB in Ubuntu

Step 1 - Importing the Public Key

GPG keys of the software distributor are required by the Ubuntu package manager apt (Advanced Package Tool) to ensure package consistency and authenticity. Run this command to import MongoDB keys to your server.

Step 3 - Create the root user

Desc: Create user admin with password admin123 and have the permission/role as root and the database is admin.

Now type exit to exit from MongoDB shell.

Step 4 - Edit MongoDB configuration file

Edit the MongoDB configuration file /etc/mongod.conf with an editor.

nano /etc/mongod.conf

Uncomment the line #auth = true by removing the # character, then save and exit.

Step 5 - Restart MongoDB and try to connect

Now restart MongoDB and connect with the user created.

sudo service mongod restart

and connect to the mongodb shell with this command:

mongo -u admin -p admin123 --authenticationDatabase admin

and you will see the output like this:

Conclusion

A well-known NoSQL database that offers high performance, high availability, and automatic scaling is MongoDB. It is different from the RDBMS such as MySQL, PostgreSQL, and SQLite as it does not use SQL to set and retrieve data. MongoDB stores data in `documents` called BSON (binary representation of JSON with additional types of information). MongoDB is only available for 64-bit Long Term Support Ubuntu Release.

Starting a shell, attempting to connect to a non-running database (connection refused)
Starting the database, seeing 0 connections in the logs
Stopping the database (Ctrl-C or similar), starting a shell, fails to connect again because database has been shut down
Starting the database, seeing 0 connections in logs
repeat

I installed clients tools on the application server and tried to connec to database mongodb on another server and I have all time connection refused and when I saw the mongodb errorlog there is no error. I think I am missing something. Could you provide me with the rigth mongo syntax to connect